This subclass of Net::Async::FastCGI provides a slightly different API;
where it can take an argument containing the IO::Async::Loop object, rather
than be added as Notifier object within one. It is provided mostly as a
backward-compatibility wrapper for older code using this interface; newer
code ought to use the Net::Async::FastCGIinterface directly.

If either a handle or service argument are passed to the constructor,
then the newly-created object is added to the given IO::Async::Loop, then
the listen method is invoked, passing the entire %args hash to it.

If either of the above arguments are given, then a IO::Async::Loop must
also be provided: